How to Stabilize Spalted Wood #1: Building a Pickle Jar Vacuum Chamber

Spalted wood is beautiful stuff, most woodworkers will agree to that. However it has its drawbacks due to the spalting process is caused by fungi attacking the wood cells. Spalted wood is essentially partially decomposed wood and therefore has soft spots and ink lines and spongy areas that make it unsuitable for some uses. I have some spalted apple that I want to use for tool handles, in order for this beautiful wood to hold up to the abuses I put my tools through I will have to stabilize it in acrylic resin. This is how it is done. First you must build a vacuum chamber, that might seem intimidating at first, but it is neither hard or expensive.

Here is what you need to get started. A pickle jar that is large enough to hold the piece of wood you want to stabilize, the wood has to be completely immersed in the resin. The jar in the photo is a quart or 32 oz jar. A brake bleeder, available from Harbor Freight for around $25 or less if you have a coupon. A 1/4 inch brass barb connector, available at Ace hardware or your local BORG. You will also need some epoxy resin or even better some JB Weld.

First step is to drill a hole in the lid large enough for the barb fitting.

I used a 19/64ths drill bit.

Then scuff the area around the hole and the fitting and set it in place with epoxy or JBWeld. The photos show epoxy but I have had better luck using JBWeld, sometimes the epoxy won’t bond to lid as well and will break free.

The next step is work on the wood, These pieces of wood were dipped in paraffin, here I have scraped it all off.

You will need to size your pieces of wood so that they fit in the pickle jar with room on top to be completely immersed and also have room to add weight. The wood will want to float in the resin so I add a small stone on top of the piece to weight it down so that it stays completely submerged. This essentially completes the vacuum chamber, all that is left is to slip the tubing that comes w/ the brake bleeder over the barb fitting. I like to heat the tubing first in hot water or with a heat gun on low setting. This is how it should look when you are done.

That is all for now. In the next entry I’ll show the rest of the story.